AISI  1045 is a medium carbon steel designed to be able to function in areas  requiring greater strength and hardness. This steel possesses excellent size  accuracy, concentricity, and straightness which together minimize wear in  high speed applications. AISI 1045 can be formed into turned, ground and  polished coils that  can be machined unsymmetrically with limited distortion. They are often used in the production  of gears, shafts, axles, bolts, studs and  machine parts.